Telephone system



June 9, 1925.

A. F. KANE TELEPHONE SYSTEM Filed April 10, 1923 2 Sheets-Sheet l Q l L E. aww, .m mm.

Kane

Affi/r,

A/fr

June 9, 1925. 1,541,359

A. F. KANE TELEPHONE SYSTEM Filed April 10. 192:5 2 :Sheets-Sheet 2 A /nvno/*J Alfred F. Kane Patented June 9, 1925.

UNITED STATES PATENT OFFICE.

ALFRED F. KANE, OF NEW YORK, N. Y., ASSIGNOR T WESTERN ELECTRIC, COMPANY,

INCORPORATED, 0F NEW YORK, N. Y., A. CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application filed April 10, 1923'. Serial No. 631,132.

To all wzom t may concer/i:

Be it known that I, ALFRED F. KANE, a citizen of the United States of America, residing at New York, in the county of lBronx and State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephonek systems and more particularly to switching apparatus of the so-called coordinate type.

Heretofore in systems of this type as disclosed in a copending application of E. H. Clark, Serial No. 608,139, filed December 21, 1922, it has been pro sed to distribute t-raiiic over a plurality o common connecting links by assigning a' group of lconnecting link circuits to a group ofsubscribers lines, and providing a separate starting conductor for each line, and a relay -for each group of links for connectin each offsaid starting conductors to adi erent one of said links, from whence the selection of an idle link by said lines ma proceed.

From the oregoing yit is evident that the even distribution of wear on a group of connecting links depends upon the manner in which calls emanate from the lines having 30 raccess to the group of links, that is, in order to have an absolutely even distribution of wear on the connecting links it is necessary that subscribers on the lines associated therewith initiate calls in a certain sequence, a condition which will be rarely met with in practice.

It is, therefore, an object of this invention to evenl distribute the wear on the connecting inks of a coordinate switch, irrespective of the manner in which'calls, which are to be handled by the links, are initiated.

The foregoing object of this .invention is obtained by providingeach link in a group with a link relay, and a common locking circuit for all such relays in a group which is controlled by the last relay in the group, so that as each link has beenseized for use its associated link relay locks up under control ot' the last link relay in the group, thereby rendering the link associated therewith inaccessible to incoming calls until all other succeeding links have been utilized in extending connections. The operation of the controlling link relay opens the common locking circuit and permits all the individual link relays to release, thereby again rendering the links successively accessibley to incoming calls. By this arrangement no link connector can be employed a second time until all other link connectors in the group have been used once in extending connections.

lOther features and advantages as are contemplated by the present invention will be clearly understood from the following detailed description and by reference to the accompanying drawings in which Fig. 1 shows two groups of incoming lines, and Fig. 2 shows two groups of link circuits adapted to interconnect the lines incoming from the groups shown in Fig. 1 with the outgoing trunks shown on the right of Fig. 2.

The following description is directed only to the operation of the circuits employed in switches of this type, but a clear understandingof the type of mechanical apparatus, which may be employed in connection with these circuits, may be had from the British patent No. 183,488, issued to Western Electric Company, Limited, accepted Sepytember 6, 1923.

Referring to the drawing, there are shown two groups of two incoming lines, the upper group containing lines 20 and 21 and the lower group containing lines 22 and `23.

yLet it be assumed that the'subscriber on line 21 wishes to establish a. connection. The

followingdescription will show how upon.

the removal of the receiver on line 21 this lishes a circuit for theenergization of line relay 24. This circuit extends from grounded battery, left-hand ywinding of relay2/1, back contact and outer armature of cut-off relay 25 over the closed loop of line 21, inner armature and back contact of relay 25 and thence to ground through the right-hand winding of line relay 24. The operation of relay 24 establishes a circuit from grounded battery, winding of vertical line magnet 28, conductor 29, armature and front contact of line rela 24, winding of relay26, normal make-be ore-break contacts of relay 26, conductor 27, conductor 30, back contact and upper armature of relay 31, conductor 32 to ground over the back contact and upper When trunk 100 is found busy relay 39 is energized so that a second call initiated in ner similar to magnet 40 as hereinbefore described.

It is to be noted that when relay 54 is energized, and locks up under the control 0f relay 110 a call emanating from line 20, which would effect the operation of vertical line magnet 70, would be handled over conductor 47 as before, but the circuit for magnet 43 would be found open at the righthand back contact of relay 54 whereupon the connection would be transferred to link 102 by the energization of magnet 44 over the right-hand armature and yfront contact of relay 54 and right-hand arma-ture and back contact of relay 90. This condition prevails whether or not link 101 is still in use since relay 54 locks up independentlyl of magnet 43 and remains energized after link 101 has been released and until links 102, 103 and 104 have been sequentially'employed in extending connections.

As soon as the link 104 has been seized for the extension of a call and magnet 46 haslocked up under the controlof a relay Inman iiiii .i

such as 39, relay 110 becomes energized in a mannersimilar to that described in connection with relay 54. f Relay 110 in attracting its left-hand armature interrupts the common locking circuit for relays 112, and 54v permitting these relays to release and rendering the links 101, 102 and 103 again successively accessible to incoming calls. From the foregoing it is evident that the system disclosed provides for the absolute even distribution of wear on the link connectors in a group irrespective of the manner in which the calls emanate from the lines having access to the roup.

Sonie of the general features of this system which are included in the British patent mentioned above are first, the lines in a vertical or longitudinal row above magnet 28 forin one digital subgroup and, second, the lines in a horizontal or transverse row to the right of the group of magnets 43 to 46 form another digital subgroup. These subgroups may be said to be in the two principal directions of a two coordinate system and hence in a hundred line main group there will be twenty digital subgroups ten of which will be characterized by a tens digit, and the remaining ten will be characterized by a units digit.

All the link circuits have access to the trunks such as 100 and 105. The link circuits are, however, divided into groups and each group of link circuits is individual to a particular group of linesiii one direction of the two coordinate system, thus the group of link circuits includinglinks 101, 102, 103 and 104 is individual to the particular group containing lines 20 and 21, etc., and forms a krow of contact sets for each line and trunk bar.

lt should be noted that magnet 28 upon energizing opens its outer right-hand armature contacts and removes battery potential from the winding of all other magnets cori responding to magnet 28 such as magnets 70, 51, 93 and and 52, etc., serving other lines of the saine or another subgroup as 'for 'example lines 20 and 22, so that should a call be simultaneously' initiated upon an-r other line served by such other magnets no interference will result and the possibility of double connections to the saine link eireuit is obviated. In like manner the remaining magnets 70, 51, 93 etc., disconnect battery from all other magnets succeeding them in order in such a manner that it is not possible for tivo such magnets to become energized at the saine time, the magnet nearest the source of potential being" given the pre-ference. Y i

Il two lines in different groups, for example, lines 21 and 23 both served by the san'ie magnet 28 call simultaneously the connection of both lines to the same trunk circuit through different link circuits is prevented since it is not possible-.for link bar magnets suoli as 43 and 95 serving respectively the groups of lines in which lines 21 and lterminate to become simultaneously operated. The simultaneous operationy of rmagnets 43 and during the operation of trunk bar magnet 40 (such operations would pei-nii( lines 21 and 23 to be simultaneously connected to trunk is prevented by the operation of relay 33, which at its upper armuture opens the initial energizing circuit for relay 26 which controls the operation of relay 31. Thus if lilies 21 and 23 siniultaueously initiate calls line 23 will have preference, but if line 21 initiates a call just a small fraction of a second prior to line 23, relay 31 will have become operated and will have opened the initial energizing circuit for relay 98.

What is claimed is:

1. In atelephone system, a plurality of incoming lines, a-group of link circuits, a relay common to all of said lines,a relay individual to a particular one of said lines, and'means effective upontlie conjoint operation of said relays to select one of said link circuits to cooperate with one of said lines in establishing a. telephonie connection, and to render the selected link for other connections until all the links in said group have been employed.

inaccessible Q. The combination in :1 switching' system uit line circuit-s, link circuits, trunk circuits, line bers seiw'ingv said lines, link onrs serving; said links, i1 trunk bnr 'for ezu'h ot said trunks, meiins tor efuisiiig` the t opera.- tion ot' i1 line bnr, n link bnr :1nd 11 trunk bnr, sfiid bars cooperatingl with euch other in connecting); n line to 11 link and such linkto a trunk, and menus tor rendering' u selected link inaccessible until all of said links have been used.

3. The conibinnion in n switching; system et' line circuits, link circvits, trunk circuits, Contact sets, line bers seriing' said lines, link bars serving sziid links. :1 trunk bar for each ot said trunks, means or causing the joint. operation ot the line bnr, a link bar 11nd n trunk ber, said bers cooperating with eat-l1 other in nctue. ingr said contact sets to connect i1 line to l ik nnd sneh link to :1 trunk, :1nd means for rendering i1 selected link in accessible until all o1 said links hure been used.

hl. The Combination in i1 switching system ot line circuits, link circuits, trunk circuits, line bars serving' seid lines, link bars serving' said links, n trunk bnr for each of said trunks, means for causing the joint Operntion ot a line bar, 21 link bnr :1nd av trunk bnr, said bers cooperating with each other in connecting' n line to :1 link 21nd such link to :i trunk, relay ineens for rendering; n. selected link inaccessible until all ot' said links have been used, :1nd ineens t'or releasing the line :1nd trunk bars.

rl`l1e coirbiniition in 1 switching system ot line circuits, link circuits, trunk circuits, line bars serving snidlines, link bers serving,r said links, a trunk bnr Jfor euch of said trunks, means 'for causing' the joint operailion ot 21` line bnr, :1 link bur 11nd :1 trunk bnr, snid bars cooperatingr with ciu-l1 other in connecting :1 line to n link und such link to :1 trunk, relay means tor renderingA a. selected link inaccessible until :ill ot' said linksl have been used, means for releasingr the line :1nd trunk bars, and ineens controlled b v the link bnr., t'or maintaining' tlie established connection.

G. The combination in n switching system ot' lines divided into subgroups, a group of links tor each Subgroup ot lines. trunks serving,r all ot' said links` line switching members each serving; n line in each sub- Agroup, link switeliing members individual] lo skid links, trunk switching members individual to snid trunks, means tor causingv the joint operation of one of each of said sriteliiiner members to connect :1 line to` :1 link and such link to :1y trunk, :1nd relay means t'or rendering.T :1 selected link inaccessible until all ot suid links have beenused,

7. The combination in 11 switching,T system ol lines divided into subgroups, :1- group nl links for each subgroup ol" lilies. trunks serving ull ot' said links, line switching members, euch serving i1 line in euch subgroup, link switching members individual to said links, trunk switching' members individuzll to said trunks, means for cnusin} r the joint operation of one of enc-l1 ot said switching members, :1nd relay means for rendering :1 selected hnk mnccessible until allot said links have been used.

In witness whereof, I hereunto subscribe my 11i1metl11s 7th day of Aprll A. D., 1923.

ALFRED F. KANE. 

